Discover November/December 2021

When I was a kid, I wanted to be a detective. Thanks to a steady diet of the Hardy Boys and Encyclopedia Brown, though, I had a very simplistic view of things. I didn’t at first appreciate that, in the real world, investigating crimes and analyzing evidence was the work of many different kinds of experts behind the scenes, not just one or two know-it-alls. My parents tried to leaven my ignorance somewhat with more detailed books and, one Christmas, the gift of a fingerprint kit. It was pretty cool, with vials of wonderfully messy graphite dust and baby powder to capture prints on light and dark surfaces. Other items included a magnifying glass; tape strips for lifting prints; and instructions for analyzing fingerprints, which the text assured me was an…

OVERPOPULATION EXTRAPOLATION (“How to Save Planet Earth,” May 2021) Let me recommend adding a curve for the human population to your graph of the CO2-loading of the atmosphere. The two will roughly coincide starting about two centuries ago because the growth in the human population is the root cause of all environmental issues, but is never mentioned in articles such as yours. The global population has roughly quadrupled during my lifetime, destroying habitats, increasing the resources consumed, and generating waves of refugees. Without the growth in human numbers, none of these problems would have occurred. Yale Zussman You continue to step away from the major cause of most of today’s problems. Saving the Earth cannot be accomplished by conservation, science, and technology as long as human overpopulation is not addressed. This is apparently a…

SENSING TOUCH • TEEN SCIENTIST • INSIDE AN EARTHWORM HOW DID SOCIAL ANXIETY EVOLVE? • SAVING KELP FORESTS • TIKTOK TREND STAR BURST This Funfetti-like bloom called Cassiopeia A shows the aftermath of a supernova, or a massive star explosion, about 11,000 light-years from Earth. The vibrant colors added to this image denote the elements detected within it; for example, the blue blobs are titanium, iron is orange and oxygen is purple. While astronomers aren’t certain how some giant stars explode, Cassiopeia A is providing some clues. Using nearly two decades worth of data from NASA’s Chandra X-ray Observatory, scientists discovered bubbles of titanium — the same element used to make your electronics and jewelry — that could have boosted the boom’s shock wave.…

Several years ago, Sushma Subramanian was procrastinating on her work when she noticed her desk was a bit wobbly. It was a rather mundane moment, she recalls. But as she began to fiddle with the tabletop, the science journalist found herself noting how the experience felt: the grain of the wood against her fingers, the pinching of her skin and the sensation of her muscles straining to lift the desk. As Subramanian explains in her book, How to Feel: The Science and Meaning of Touch (Columbia University Press, 2021), it was a moment when she began to consider how little she knew about this multifaceted sense. The questions kept forming, eventually leading Subramanian to write an article for Discover in 2015 about the development of tactile touch screens. In her latest work,…

Shreya Ramachandran, 18, remembers witnessing California’s water crisis firsthand on a visit to Tulare County in 2014, when she was still a preteen. Tulare spans a large swath of farmland in California’s Central Valley, and at that time, locals were facing dire water shortages amid an ongoing drought made worse by climate change. “I was talking to some of the people in the area whose wells completely ran dry, and they were left without water because they weren’t connected to the central water grid,” she says. “They were trucking water in for even basic needs.” Ramachandran, who lives in Fremont, California, was spurred by the experience to find ways to reuse water from sinks, showers and laundry machines — what’s known as gray water — to help people better cope with intense…

The jewel-like tones in this image reveal the rich interior life of an earthworm — and not just metaphorically speaking. Worms play host to a legion of symbiotic microbes and parasites, which leave behind distinct molecular fingerprints. This past July, researchers at the Max Planck Institute for Marine Microbiology in Germany combined two different imaging methods to look at how those molecular signals are distributed throughout a worm’s body. The vibrant colors in the top half of this cross-section represent different metabolites — small molecules that regulate functions such as immune responses — in the worm’s tissue, while the bottom shows the underlying tissue structure. Together, these imaging techniques reveal the interplay between the worm and its parasites on a molecular level, and could shed light on symbiotic interactions inside…